E F Johnson Company 2425341 Benutzerhandbuch
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SECURE COMMUNICATION (ENCRYPTION)
SECTION 11 SECURE COMMUNICATION (ENCRYPTION)
11.1 GENERAL
11.1.1 INTRODUCTION
This radio may be equipped to provide secure
communication on some or all channels. This feature
encrypts the voice so that it can be understood only by
someone using a radio equipped with a similar encryp-
tion device and encryption codes.
encrypts the voice so that it can be understood only by
someone using a radio equipped with a similar encryp-
tion device and encryption codes.
When a secure call is received or transmitted,
is indicated in the display (see Section 11.3.4). If
equipped with the Clear/Secure option switch and the
current channel is programmed to allow switch selec-
tion, secure communication can be manually enabled
and disabled by that switch. Otherwise, channels are
strapped to Clear or Coded operation (see Section
11.3). Secure communication can be programmed on a
per channel or per talk group basis to operate in
various ways. More information follows.
equipped with the Clear/Secure option switch and the
current channel is programmed to allow switch selec-
tion, secure communication can be manually enabled
and disabled by that switch. Otherwise, channels are
strapped to Clear or Coded operation (see Section
11.3). Secure communication can be programmed on a
per channel or per talk group basis to operate in
various ways. More information follows.
11.1.2 ENCRYPTION ALGORITHMS
SecureNet™
SecureNet encryption digitizes the voice and then
encrypts it using the DES or DVP algorithm. It uses a
64-bit encryption key. The SecureNet protocols
include the following algorithms:
64-bit encryption key. The SecureNet protocols
include the following algorithms:
•
DVP (Digital Voice Privacy) is an earlier encryption
method that is self synchronizing using cipher feed-
back. It was originally designed to be used by
anyone needing protection from unauthorized
eavesdropping.
method that is self synchronizing using cipher feed-
back. It was originally designed to be used by
anyone needing protection from unauthorized
eavesdropping.
•
DES (Data Encryption Standard) provides a higher
level of security, and also uses cipher feedback. It
was originally designed to be used only by the
Federal government.
level of security, and also uses cipher feedback. It
was originally designed to be used only by the
Federal government.
•
DVP-XL/DES-XL - A disadvantage of the DVP and
DES encryption types is reduced communication
range when compared to clear voice. The DES-XL
and DVP-XL methods were designed to provide
better range but at the cost of lower voice quality.
DES encryption types is reduced communication
range when compared to clear voice. The DES-XL
and DVP-XL methods were designed to provide
better range but at the cost of lower voice quality.
They use a different type of feedback called counter
addressing.
addressing.
•
DES-OFB - A form of DES encryption for digital
channels that uses output feedback. This protocol
does not result in the degraded range that occurs
with analog channels.
channels that uses output feedback. This protocol
does not result in the degraded range that occurs
with analog channels.
AES (Advanced Encryption Standard)
A new encryption standard called AES is
replacing DES-OFB encryption on digital (P25) chan-
nels. It uses a 128-, 192-, or 256-bit encryption key
instead of the 64-bit key used with DES. EFJohnson
radios currently support only 256-bit AES keys. The
type of encryption (DES or AES) is determined by the
type of encryption key that is loaded (see Section
11.2), and not by the PCConfigure programming soft-
ware. AES encryption, like DES encryption, is an
optional radio feature that must be purchased and then
enabled at the factory.
nels. It uses a 128-, 192-, or 256-bit encryption key
instead of the 64-bit key used with DES. EFJohnson
radios currently support only 256-bit AES keys. The
type of encryption (DES or AES) is determined by the
type of encryption key that is loaded (see Section
11.2), and not by the PCConfigure programming soft-
ware. AES encryption, like DES encryption, is an
optional radio feature that must be purchased and then
enabled at the factory.
11.1.3 ENCRYPTION AVAILABLE WITH
VARIOUS CHANNEL TYPES
Analog Channels
On analog conventional and SMARTNET/Smart-
Zone channels, DES and DES-XL encryption is used
to provide secure communication. The DES-XL type
is available only with 5300 mobiles equipped with the
Motorola UCM (Universal Crypto Module). Refer to
the next section for more information.
to provide secure communication. The DES-XL type
is available only with 5300 mobiles equipped with the
Motorola UCM (Universal Crypto Module). Refer to
the next section for more information.
Digital Channels
On digital Project 25 and SMARTNET/Smart
Zone channels, the DES-OFB or AES protocol is used
(AES is available with ARM code 1.20.0 or later and
all 2.0/3.0). Refer to Section 11.1.4 for more
information.
(AES is available with ARM code 1.20.0 or later and
all 2.0/3.0). Refer to Section 11.1.4 for more
information.
11.1.4 5300 ENCRYPTION CAPABILITIES
As described in Section 9, there are now three
different 5300 versions which provide various
encryption capabilities.
encryption capabilities.